diff options
Diffstat (limited to 'arch/metag/mm/fault.c')
| -rw-r--r-- | arch/metag/mm/fault.c | 247 |
1 files changed, 0 insertions, 247 deletions
diff --git a/arch/metag/mm/fault.c b/arch/metag/mm/fault.c deleted file mode 100644 index de54fe6..0000000 --- a/arch/metag/mm/fault.c +++ /dev/null @@ -1,247 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * Meta page fault handling. - * - * Copyright (C) 2005-2012 Imagination Technologies Ltd. - */ - -#include <linux/mman.h> -#include <linux/mm.h> -#include <linux/kernel.h> -#include <linux/ptrace.h> -#include <linux/sched/debug.h> -#include <linux/interrupt.h> -#include <linux/uaccess.h> - -#include <asm/tlbflush.h> -#include <asm/mmu.h> -#include <asm/traps.h> - -/* Clear any pending catch buffer state. */ -static void clear_cbuf_entry(struct pt_regs *regs, unsigned long addr, - unsigned int trapno) -{ - PTBICTXEXTCB0 cbuf = regs->extcb0; - - switch (trapno) { - /* Instruction fetch faults leave no catch buffer state. */ - case TBIXXF_SIGNUM_IGF: - case TBIXXF_SIGNUM_IPF: - return; - default: - if (cbuf[0].CBAddr == addr) { - cbuf[0].CBAddr = 0; - cbuf[0].CBFlags &= ~TXCATCH0_FAULT_BITS; - - /* And, as this is the ONLY catch entry, we - * need to clear the cbuf bit from the context! - */ - regs->ctx.SaveMask &= ~(TBICTX_CBUF_BIT | - TBICTX_XCBF_BIT); - - return; - } - pr_err("Failed to clear cbuf entry!\n"); - } -} - -int show_unhandled_signals = 1; - -int do_page_fault(struct pt_regs *regs, unsigned long address, - unsigned int write_access, unsigned int trapno) -{ - struct task_struct *tsk; - struct mm_struct *mm; - struct vm_area_struct *vma, *prev_vma; - siginfo_t info; - int fault; - unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; - - tsk = current; - - if ((address >= VMALLOC_START) && (address < VMALLOC_END)) { - /* - * Synchronize this task's top level page-table - * with the 'reference' page table. - * - * Do _not_ use "tsk" here. We might be inside - * an interrupt in the middle of a task switch.. - */ - int offset = pgd_index(address); - pgd_t *pgd, *pgd_k; - pud_t *pud, *pud_k; - pmd_t *pmd, *pmd_k; - pte_t *pte_k; - - pgd = ((pgd_t *)mmu_get_base()) + offset; - pgd_k = swapper_pg_dir + offset; - - /* This will never happen with the folded page table. */ - if (!pgd_present(*pgd)) { - if (!pgd_present(*pgd_k)) - goto bad_area_nosemaphore; - set_pgd(pgd, *pgd_k); - return 0; - } - - pud = pud_offset(pgd, address); - pud_k = pud_offset(pgd_k, address); - if (!pud_present(*pud_k)) - goto bad_area_nosemaphore; - set_pud(pud, *pud_k); - - pmd = pmd_offset(pud, address); - pmd_k = pmd_offset(pud_k, address); - if (!pmd_present(*pmd_k)) - goto bad_area_nosemaphore; - set_pmd(pmd, *pmd_k); - - pte_k = pte_offset_kernel(pmd_k, address); - if (!pte_present(*pte_k)) - goto bad_area_nosemaphore; - - /* May only be needed on Chorus2 */ - flush_tlb_all(); - return 0; - } - - mm = tsk->mm; - - if (faulthandler_disabled() || !mm) - goto no_context; - - if (user_mode(regs)) - flags |= FAULT_FLAG_USER; -retry: - down_read(&mm->mmap_sem); - - vma = find_vma_prev(mm, address, &prev_vma); - - if (!vma || address < vma->vm_start) - goto check_expansion; - -good_area: - if (write_access) { - if (!(vma->vm_flags & VM_WRITE)) - goto bad_area; - flags |= FAULT_FLAG_WRITE; - } else { - if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))) - goto bad_area; - } - - /* - * If for any reason at all we couldn't handle the fault, - * make sure we exit gracefully rather than endlessly redo - * the fault. - */ - fault = handle_mm_fault(vma, address, flags); - - if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) - return 0; - - if (unlikely(fault & VM_FAULT_ERROR)) { - if (fault & VM_FAULT_OOM) - goto out_of_memory; - else if (fault & VM_FAULT_SIGSEGV) - goto bad_area; - else if (fault & VM_FAULT_SIGBUS) - goto do_sigbus; - BUG(); - } - if (flags & FAULT_FLAG_ALLOW_RETRY) { - if (fault & VM_FAULT_MAJOR) - tsk->maj_flt++; - else - tsk->min_flt++; - if (fault & VM_FAULT_RETRY) { - flags &= ~FAULT_FLAG_ALLOW_RETRY; - flags |= FAULT_FLAG_TRIED; - - /* - * No need to up_read(&mm->mmap_sem) as we would - * have already released it in __lock_page_or_retry - * in mm/filemap.c. - */ - - goto retry; - } - } - - up_read(&mm->mmap_sem); - return 0; - -check_expansion: - vma = prev_vma; - if (vma && (expand_stack(vma, address) == 0)) - goto good_area; - -bad_area: - up_read(&mm->mmap_sem); - -bad_area_nosemaphore: - if (user_mode(regs)) { - info.si_signo = SIGSEGV; - info.si_errno = 0; - info.si_code = SEGV_MAPERR; - info.si_addr = (__force void __user *)address; - info.si_trapno = trapno; - - if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) && - printk_ratelimit()) { - printk("%s%s[%d]: segfault at %lx pc %08x sp %08x write %d trap %#x (%s)", - task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG, - tsk->comm, task_pid_nr(tsk), address, - regs->ctx.CurrPC, regs->ctx.AX[0].U0, - write_access, trapno, trap_name(trapno)); - print_vma_addr(" in ", regs->ctx.CurrPC); - print_vma_addr(" rtp in ", regs->ctx.DX[4].U1); - printk("\n"); - show_regs(regs); - } - force_sig_info(SIGSEGV, &info, tsk); - return 1; - } - goto no_context; - -do_sigbus: - up_read(&mm->mmap_sem); - - /* - * Send a sigbus, regardless of whether we were in kernel - * or user mode. - */ - info.si_signo = SIGBUS; - info.si_errno = 0; - info.si_code = BUS_ADRERR; - info.si_addr = (__force void __user *)address; - info.si_trapno = trapno; - force_sig_info(SIGBUS, &info, tsk); - - /* Kernel mode? Handle exceptions or die */ - if (!user_mode(regs)) - goto no_context; - - return 1; - - /* - * We ran out of memory, or some other thing happened to us that made - * us unable to handle the page fault gracefully. - */ -out_of_memory: - up_read(&mm->mmap_sem); - if (user_mode(regs)) { - pagefault_out_of_memory(); - return 1; - } - -no_context: - /* Are we prepared to handle this kernel fault? */ - if (fixup_exception(regs)) { - clear_cbuf_entry(regs, address, trapno); - return 1; - } - - die("Oops", regs, (write_access << 15) | trapno, address); - do_exit(SIGKILL); -} |
